PURIFICATION AND CHARACTERIZATION OF THE LIPASE FROM SERRATIA-MARCESCENS SR41-8000 RESPONSIBLE FOR ASYMMETRIC HYDROLYSIS OF 3-PHENYLGLYCIDIC ACID-ESTERS
H. Matsumae et T. Shibatani, PURIFICATION AND CHARACTERIZATION OF THE LIPASE FROM SERRATIA-MARCESCENS SR41-8000 RESPONSIBLE FOR ASYMMETRIC HYDROLYSIS OF 3-PHENYLGLYCIDIC ACID-ESTERS, Journal of fermentation and bioengineering, 77(2), 1994, pp. 152-158
A new lipase which enantioselectively hydrolyzes (+/-)-trans-3-(4-meth
oxyphenyl)glycidic acid methyl ester [(+/-)-MPGM], a key intermediate
in the synthesis of diltiazem hydrochloride, was purified from the cul
ture supernatant of Serratia marcescens Sr41 8000. The apparent kineti
c constants (K(m), V(max)) for hydrolysis of (2S,3R)-MPGM [(+)-MPGM] w
ere 350 mM and 1.7 x 10(-3) mol/min/mg protein in a toluene-water (1 :
1) emulsion system. The lipase did not attack (2R,3S)-MPGM [(-)-MPGM]
, and (-)-MPGM acted as a competitive inhibitor. The molecular mass wa
s estimated to be 62,000+/-2,000 from SDS-PAGE. The lipase preferentia
lly hydrolyzed (2S,3R)-3-phenylglycidic acid esters, but did not hydro
lyze cinnamic acid esters. The lipase released glycerol and fatty acid
from olive oil, and the optimum pH and temperature for hydrolysis of
olive oil were pH 8 and 45-degrees-C, respectively. The lipase was inh
ibited by Co2+, Ni2+, Fe2+, Fe3+ and EDTA, and activated by Ca2+, Liand SDS. It was presumed that the lipase was a metalloenzyme containin
g approximately one gram atom of calcium per molecular mass of 62,000.
The lipase selectively hydrolyzed the 1,3 ester of triglycerides. Seq
uencing of the N-terminal amino acids revealed that this lipase was di
stinct from other known lipases.